Signal reproducing/recording/transmitting method and apparatus and signal record medium

ABSTRACT

A signal reproducing apparatus for prohibiting copying or unauthorized use. The apparatus includes a copying management information decision circuit  19  for discriminating the state of the copying management information read out from each header of a data sector and within the TOC, a protect signal generating circuit  20  for generating a protect signal based on the discrimination signal and a mixing circuit  24  for mixing a protect signal in a vertical blanking period of an analog video signal D/A converted from digital video data reproduced from an optical disc D. The apparatus also includes a descrambling circuit  31  for descrambling the digital data based on the copying management information and a scrambling circuit  32  for descrambling the digital data. The apparatus enables prohibition of unauthorized analog copying and digital copying, inhibition of serial generational copying and prohibition of unauthorized analog and digital copying simultaneously.

This application is a con of Ser. No. 08/690,224 Jul. 19, 1996.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a signal recording apparatus, a signal record(recording , recordable or recorded) medium and a signal reproducingapparatus for prohibiting copying or unauthorized use.

2. Description of the Related Art

Recently, with increased capacity and coming into widespread use ofdigital recording media, such as optical discs, prohibition ofduplication or unauthorized use thereof has become crucial forprotecting the copyright of recorded signals. That is, digital audiodata or digital video data can be duplicated by copying or dubbingwithout deterioration, while computer data can be duplicated to givedata which are the same as the original data, thus giving rise totroubles, such as copyright infringement, due to unauthorized copying.

With this in view, a pre-set ID bit for preventing unauthorized copyingis occasionally recorded on an original signal record medium forprohibiting unauthorized copying in so-called digital dubbing in whichdata is reproduced from a digital record medium and re-recorded onanother digital record medium.

For example, in a system for prohibiting the unauthorized copying in adigital audio data recording/reproducing apparatus termed a rotary headdigital audio tape recorder (R-DAT), an inhibiting code for inhibitingdigital copying or generation-serial copying, that is for copyinggeneration limitation (inhibiting code of a standard of the serialcopying management system or SCMS) is recorded in a main data area fordigital audio signals recorded on a digital audio tape as a signalrecord medium, so that, when the inhibiting code is detected by thedigital audio signal recording apparatus, copying recording of thedigital audio signals on a new digital audio tape is inhibited.

Meanwhile, in digital dubbing of video signals, in which digital videosignals, for example, recorded on a digital record medium, such as adigital disc or a digital tape, are reproduced and re-recorded onanother record medium, a pre-set ID bit, that is the inhibiting code ofa standard of the serial copying management system (SCMS), may berecorded in the original digital record medium.

In case of a recording system of recording the pre-set ID bit forprohibiting the unauthorized copying on the original digital recordmedium, the function of preventing unauthorized copying in theabove-described digital dubbing operates satisfactorily. However, incase the digital video signals recorded on an original digital recordmedium are reproduced and D/A converted for analogically recording theconverted analog video signals, or in case the analog video signals areagain A/D converted for recording in the digital form, the function ofpreventing unauthorized copying fails to operates satisfactorily, sothat recording can be made directly.

That is, if the digital video signals recorded on the digital recordmedium is reproduced and D/A converted and the resulting analog videosignals are directly recorded analogically or restored by A/D conversionto digital video signals for digital recording, the video signalsresulting from dubbing are deteriorated in signal quality to anextremely small extent. This means that copyright protection ia notassured sufficiently, and hence a system is required which positivelyprohibits such unauthorized copying. In particular, large-capacitydisc-shaped recording media have recently become popular, such that ademand has been raised for suitable measures against unauthorizedcopying of digital video signals recorded on the disc-shaped recordmedium.

On the other hand, if the pre-set ID bit provided for prohibitingunauthorized copying is skipped in reading, unauthorized copying can beachieved easily. Therefore, suitable measures for prohibitingunauthorized copying by skipping in reading have also been desired.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a signalreproducing method and apparatus, a signal recording method andapparatus, a signal transmitting method and apparatus and a signalrecord(recording, recordable or recorded) medium whereby it is possibleto prevent unauthorized copying by skipping in reading and it is alsopossible to inhibit unauthorized copying of analog signal converted fromdigital data digitally or analogically as well as to inhibitgeneration-serial copying.

With the method and apparatus for reproducing a signal according to thepresent invention, digital data or an analog signal D/A converted fromthe digital data are converted in a pre-set manner based on therecording control information arrayed in a playback mode control signalarea and/or each sector header of a signal record medium.

With the method and apparatus for recording a signal according to thepresent invention, a signal is ciphered using at least a portion of therecording control information designed for controlling the recording ona signal record medium as the key information, or by the key informationspecified by at least a portion of the recording control information,with this recording control information being arrayed at a pre-setposition of a playback mode control signal area of the signal recordmedium and/or at a pre-set position of each signal recording unit on thesignal record medium and being recorded along with the ciphered signalon the signal record medium.

With the method and apparatus for transmitting a signal according to thepresent invention, digital data or an analog signal D/A converted fromthe digital data are converted in a pre-set manner based on therecording control information ancillary to transmitted digital data.

With the method and apparatus for transmitting a signal according to thepresent invention, the signal is ciphered using at least a portion ofthe transmission management information designed to supervise signaltransmission as the key information, or by the key information specifiedby at least a portion of the recording control information and thetransmission management information is transmitted along with theciphered signal.

With the signal record medium of the present invention, the recordingcontrol information for supervising the signal recording on the signalrecord medium is recorded at a pre-set position in a playback modecontrol signal area and/or at a pre-set position in each signalrecording unit. At least a portion of the recording control informationis used as the key information for ciphering the recording signal.

That is, with the present invention, both digital data and the analogsignal are converted in a pre-set manner based on the recording controlinformation or the transmission control information. The pre-setconversion may be ciphering or scrambling, for example, for digital dataand for analog signals, respectively, whereby both the unauthorizeddigital copying and unauthorized analog copying may be prohibited fromoccurring. According to the present invention, since the signal isciphered based on the recording control information or the transmissioncontrol information, deciphering is not feasible if the reading of therecording control information or the transmission control information isskipped, thus enabling prevention of unauthorized copying.

With the video signal reproducing apparatus and method of the presentinvention, a digital signal is reproduced from a digital disc mediumhaving recorded thereon the video recording control code arrayed in aplayback mode control signal recording area provided at a beginning endof a spirally extending recording track and/or in each header of thedigital video signal divided into sectors, along with the digital videosignal, for ultimately producing at least the analog video signaloutput. The state of the video recording control code is detected, andthe video recording scrambling signal of the mode of the analog videosignal and/or the recording inhibiting signal is generated on the basisof the detection output. The video recording scrambling signal and/orthe video recording inhibiting signal is annexed in a pre-set area ofthe vertical blanking period of the analog video output signal convertedfrom the digital video signal and the resulting analog video signal isoutputted.

With the video reproducing/recording combination apparatus and method ofthe present invention, a digital disc medium, having recorded thereonthe digital video signal and the video recording control signal, isreproduced for outputting at least the analog video signal, and theoutput analog video signal is recorded. The video recording scramblingsignal of the analog signal mode is generated based on a statusdetection output of the video recording control code. The generatedvideo recording scrambling signal is annexed in a pre-set area of avertical blanking period of the analog video signal converted from thedigital video signal, and the resulting analog video signal isoutputted. Also the input analog video signal, amplitude-adjusted by anautomatic amplitude adjustment unit, which is responsive to the videorecording scrambling signal contained in the input analog video signal,is recorded on an analog video record medium.

With the video reproducing/recording combination apparatus and method ofthe present invention, a video recording inhibiting signal of the analogvideo signal mode is generated on the basis of a state detection outputof the video recording control code. The generated video recordinginhibiting signal is annexed in a pre-set area of a vertical blankingperiod of an analog video signal obtained on conversion of the digitalvideo signal, and the resulting analog video signal is outputted. Alsothe input analog video signal is recorded on an analog video recordmedium after amplitude adjustment by automatic amplitude adjustmentmeans which responds to the video recording scrambling signal containedin the input analog signal.

With the digital disc medium, designed for coping with the video signalreproducing method of the present invention, a video recording controlcode, which is a signal functioning for generating the video recordingscrambling signal and/or video recording inhibiting signal, is recordedthereon along with the digitized video signal.

That is, according to the present invention, a video recordingscrambling signal of the analog signal mode and/or the video recordinginhibiting signal is annexed to the analog video signal, D/A convertedfrom the digital video signal read out from the digital disc medium whenoutputting the analog video signal. The analog video signal, to which isannexed the video recording scrambling signal and/or the video recordinginhibiting signal, is analogically or digitally recorded on the recordmedium. The video signals reproduced from the recorded analog or digitaldisc medium is scrambled, or inhibited for video recording.

According to the present invention, both the digital data and the analogdata are converted in a pre-set manner based on the recording controlinformation and the recording control information. The pre-setconversion includes ciphering for the digital data and scrambling forthe analog data. It becomes possible in this manner to inhibitunauthorized analog or digital copying of analog signals temporarilyconverted from digital data as well as serial generation copying, whileit becomes possible to combat unauthorized copying of both the analogand digital data. In addition, since the signal is ciphered based on therecording control information or the transmission control information,deciphering becomes impossible if the recording control information orthe transmission control information is skipped in reading, thusenabling inhibition of unauthorized copying.

That is, according to the present invention, if at least the analogvideo signal is reproduced from the digital disc medium, having recordedthereon the digital video signal and the video recording control signal,arrayed in the playback mode control signal area at the beginningportion of a recording track and/or in each header of the digital videosignal divided into sectors, the video recording scrambling signaland/or the video recording inhibiting signal is generated based on thedetection output of the state of the video recording control mode andannexed in a pre-set area of a vertical blanking period of an analogvideo signal, converted from the digital video signal, and the resultinganalog video signal is outputted. If the digital disc medium is copied,it is the analog video signal, having annexed thereto the videorecording scrambling signal and/or the video recording inhibitingsignal, that is analogically or digitally recorded, such that the videosignal reproduced from the recorded analog or digital disc medium is ascrambled signal, or cannot inherently be reproduced. Thus it becomespossible with the present invention to inhibit unauthorized analog ordigital copying of analog video signals converted from the digital videosignals recorded on the digital disc medium, or to inhibit serialgenerational copying.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a step of manufacturing a master disc and a step ofreproducing a duplicated disc.

FIG. 2 illustrates the copy management information.

FIG. 3 is a circuit diagram for illustrating a scrambling circuit.

FIG. 4 illustrates the structure of an optical disc.

FIG. 5 illustrates the structure of a data sector.

FIG. 6 illustrates the structure of a TOC sector.

FIG. 7 illustrates another embodiment of a step of manufacturing amaster disc and a step of reproducing a duplicated disc.

FIG. 8 is a waveform diagram showing the state in which a protectioncode signal has been appended to an analog video signal.

FIG. 9 is a block circuit diagram showing the structure of anarrangement for prohibiting unauthorized copying in which digital videosignals are converted into analog video signals which are againconverted into analog video data for copying.

FIG. 10 is a waveform diagram showing the state in which an analogprotection code signal has been appended to an analog video signal.

FIG. 11 is a block circuit diagram showing the structure of anarrangement for prohibiting unauthorized copying in which digital videosignals are converted into analog video signals which are againconverted into an log video data for analog copying.

FIG. 12 is a waveform diagram showing the state in which an analogprotection code signal and a protect code signal have been appended toan analog video signal.

FIG. 13 is a block circuit diagram showing the structure of anarrangement for prohibiting unauthorized copying in which digital videosignals are converted into analog video signals which are analogicallyand digitally copied.

FIG. 14 illustrates another illustrative example of the copy managementinformation.

FIG. 15 illustrates a color burst inverting operation.

FIG. 16 is a circuit diagram for illustrating another example of thescrambling circuit.

FIG. 17 illustrates another example of a sector format.

FIG. 18 illustrates another embodiment of a sector header of the sectorformat of FIG. 17.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, preferred embodiments of the presentinvention will be explained in detail.

An optical disc is used as the digital record(recording, recordable orrecorded) medium of the present invention, and the process flow untilcompletion of the optical disc is explained by referring to FIG. 1.

First, in a mastering step 30 of fabricating a master disc MD, digitalvideo data converted from a motion picture film, digital data sentdirectly from a digital camera, or digital video data from a digital VTRfor a broadcasting station, are supplied to a terminal 1. The digitalvideo data, for example, supplied via the terminal 1, is sent to acompression encoding circuit 2, where it is encoded in accordance withthe so-called MPEG2 standard formulated by the Moving Picture ExpertsGroup (MPEG), at the same time as it is formed into sectors in terms ofa pre-set data volume, such as 2048 bytes, as a unit.

The data encoded for compression and formed into sectors by the encodingcircuit 2 is sent to a scrambling circuit 9. The scrambling circuit 9 isalso supplied with the copy management information for prohibitingunauthorized copying, as later explained, which is generated by a copymanagement information generating circuit 3. Output data of the encodingcircuit 2 is scrambled, as later explained, using the copy managementinformation.

The data scrambled by the scrambling circuit 9 is sent to a copyingmanagement information appending circuit. The copying managementinformation generated by the copying management information generatingcircuit 3 is also supplied to the copying management informationappending circuit, where the copying management information is appendedto output data of the scrambling circuit 9.

If a recording scrambling signal and/or a recording inhibiting signal inan analog signal format is added to the analog video signal, thescrambling circuit 9 may be omitted, in which case data from theencoding circuit 2 may be directly sent to the copying managementinformation appending circuit.

The copying management information is inserted in one or both of thelead-in area provided at a beginning end of a spirally extending trackof an optical disc at the innermost or outermost rim of the optical discand within the header of the data sector in the program area. In thefollowing description, the copying management information is appended inone or both of the TOC area and the header of the data sector. Thus thecopying management information appending circuit has an appendagecircuit 4 for appending the copying management information within theTOC and an appendage circuit 5 for appending the copying managementinformation in the data sector header.

The copying management information is made up of one or both of theinformation specifying the effect that both analog and digital copyingor only digital copying inhibition be inhibited, and the informationspecifying the effect that limitation be placed on the copyinggeneration. In the following, it is assumed that both information beincluded in the copying management information. It is possible that thecharging information be included in the copying management information.By including the charging information in the copying managementinformation, it becomes possible to make only the picture reproductionbe charge-free and to permit copying only on payment of a charged fee,that it to inhibit charge-free copying.

The copying management information for this case may be made up of eightbits b7 to b0 as shown in FIG. 2. Of these eight bits, the upper twobits b7 and b6 are allocated as a bit CM_(C) instructing generationlimitation, while the three lower bits b2, b1 and b0 are allocated asbits CM_(M) instructing copying inhibition of both digital and analogdata or only of digital data. For example, the CM_(M) bits (b2, b1, b0)of (1, 1, 1) and (0, 1, 1) mean inhibition of both digital and analogcopying and inhibition of digital copying, respectively. The bit CM_(C)allocated to generation limitation in the above copying managementinformation in the fabrication process of the master disc MD specifiesthat the disc is an original disc.

It may be contemplated to allocate only the bit b2 as a bit CM_(M)specifying that the copying be inhibited or not inhibited.

The purpose of inserting the copying management information on thesector basis is to array the information in a segmented state in a discinstead of on the overall disc surface in order to cope with differentcategories of the video signals, that is in order to accommodate thesituation in which plural sorts of video signals of different categoriesare contained in a disc and are not designed to be managed monistically,as in the case of the CD-ROM. The copying management information mayalso be appended on the block basis instead of on the sector basis.

The data to which the copying management information has been appendedby the copying management information appending circuit is sent to anencoder/modulation circuit 6. The encoder/modulation circuit 6 performsdata delaying and parity calculations, as error correction encodingoperations, on the supplied data, and modulates 8-bit data, for example,on the supplied data to form 16-channel bit modulated data in accordancewith a pre-set modulation system. The encoder/modulation circuit 6 alsoappends synchronization signals of a so-called out-of-rule patternviolating the modulation rule of the above pre-set modulation systemevery pre-set data amount and sends the resulting data to an opticalhead unit 7.

The optical head device 7 radiates a laser beam driven based on datasupplied from the encoder/modulation circuit 6 to a master disc MDrotated by a rotation servo controlled spindle motor 8 for effectingoptical recording. This completes fabrication of a master disc MD havingdata recorded thereon.

The scrambling circuit 9 is arranged as shown for example in FIG. 3.

Referring to FIG. 3, a so-called parallel block synchronization typescrambler, employing a 15-bit shift register, may be used as thescrambling circuit 9. To a data input terminal 45 of the scrambler,there is entered data comprised of 2048 byte data of a data portion ofFIG. 5 or TOC data portion of FIG. 6, from the compression encodingcircuit 2, and 4-byte error detection code (EDC), appended thereto, in asequence in which the least significant bit (LSB) comes first, that isin an LSB first sequence. The scrambling circuit 14 includes a 15-bitshift register 41 for scrambling for which feedback is applied inaccordance with a generating polynominal x¹⁵+x+1, using an exclusive OR(ExOR) circuit 42. In the 15-bit shift register 41, pre-set values orinitial values are variably set in accordance with bits b2, b1, b0(1,1,1 or 0,1,1) of the bits CM_(M) of the copying managementinformation as shown in FIG. 2 so that the pre-set values or initialvalues will be switched on the sector basis. The pre-set values may alsobe variably set by both the bits CM_(M) and CM_(C) instead of beingvariably set solely by the bit CM_(M). Output data of the shift register41 and input data from the terminal 45 are Ex-ORed by the ExOR circuit43 so as to be taken out as scrambled data at a terminal 44 and thencesupplied to the copy management information appending circuit shown inFIG. 1.

In a replication step 40, plural optical discs D are prepared by pressworking from the master disc MD produced in a manner as described above.

An disc D, duplicated from the master disc MD by the replication step40, has a center aperture 102. Looking from the inner rim towards theouter rim of the disc-shaped record medium D, there are formed a lead-inarea 103, as a program management region or TOC region, a program area104 having program data recorded therein, and a program end area, or aso-called lead-out area 105. In an optical disc for reproducing audio orvideo signals, the audio or video signals, encoded for compression asdescribed above, are recorded in the program area 104, while the timeinformation or the like for the audio or video data is managed by thelead-ion area 103. The above-mentioned copying management information isrecorded in the TOC sector of the lead-in area 103 and/or in the datasector header in the program area 104.

The structure of a data sector in the program area 104 is made up of a4-byte data sync portion D_(S), a 16-byte header portion DH, a 2048-bytedata portion D_(D) and a 4-byte error detection code (EDC) portion, witheach byte being made up of 8 bits, as shown in FIG. 5. The 1-bytecopying management information T_(P) is arrayed in a TOC data portionT_(D).

Of course, the copying management information T_(P) may be provided withthe file-based copying management information (paired data comprised ofthe file position and size and the copying management information) bybeing combined with the addresses for files. Alternatively, the numberof bytes or bits may be increased in order to have the copyingmanagement information more specific than the above-mentioned copyingmanagement information D_(P).

The above-mentioned original optical discs D may be reproduced by theuser, such as at home.

That is, returning to FIG. 1, a reproducing apparatus 50 for the opticaldisc D for household use reads out signals (RF signals) by an opticalhead unit 10 from the optical disc D run in rotation by a spindle motor10 servo-controlled for rotation by a servo circuit 13. The RF signalsread out from the optical disc D by the optical head device 10 are sentto an RF amplifier 12. The RF amplifier 12 converts the RF signals intobi-level signals when taking out signals recorded on the optical disc Dand sends the bi-level signals to a demodulating circuit 14. The RFamplifier 12 also separates synchronization signals from the RF signals,while taking out the tracking error signals and the focusing errorsignals to send the signals to the servo circuit 13. The servo circuit13 performs rotation control of the spindle motor 11 and the trackingand focusing servo for the optical head unit 10.

The demodulation circuit 14 performs demodulation, which is the reverseof the above-mentioned modulation, for converting 16 channel bit datainto 8 bit data. The digital data from the demodulation circuit 14 issent to an error correction circuit 15 for performing an operation whichis the reverse of the above-mentioned error correction encoding. Outputdigital video data of the error correction circuit 15 is resolved intosectors by a sector resolution circuit 16 and is sent via a copyingmanagement information readout circuit as later explained and adescrambling circuit 31 in this order to an expansion decoding circuit21.

The expansion decoding circuit 21 performs expansion decoding on dataencoded for compression in accordance with the above-mentioned rule forMPEG2. The expanded and decoded digital data is converted by a D/Aconversion circuit 23 into analog video signals which are sent via amixing circuit 24 as later explained to an NTSC encoder 25 forconversion into analog video signals of the so-called NTSC system of thestandard television broadcasting system. Alternatively, the digital datais outputted via the mixing circuit 24 at an analog output terminal 29as an analog video signal.

In addition, the digital data from the expansion decoding circuit 21 issent via a digital scrambling circuit 31 as later explained and adigital interfacing circuit 26 so as to be outputted as digital videodata at a digital output terminal 27.

The copying management information readout circuit includes a read-outcircuit 18 for reading out the appended copying management informationfrom the header of the data sector and a read-out circuit 17 for readingout the appended copying management information from the TOC data areaof the TOC sector, and sends the copying management information read outfrom the data of the sector resolution circuit 16 to a copyinginformation management circuit 19. If the copying management informationis appended to only one of the TOC and the data sector header, only onecorresponding circuit of the two read-out circuits 17, 18 is employed.

The copying information management circuit 19 judges which of inhibitionof analog and digital copy inhibition and inhibition of only of digitalcopying is specified by the bit CM_(M), of FIG. 2, and which generationnumber of the copying inhibition is specified by the bit CM_(C) , andoutputs a decision signal responsive to the results of decision. Thedecision signals are sent to a protect signal generation circuit 20. Thecopying information management circuit 19 sends the copying managementinformation to the descrambling circuit 31.

The descrambling circuit 31 has a structure similar to that of thescrambling circuit 9 of FIG. 3. In this descrambling circuit 31, pre-setvalues or initial values, derived from the copying managementinformation from the copying information management circuit 19, arevariably set. This allows the descrambling circuit 31 to performdescrambling, that is deciphering, which is a reverse operation of thescrambling operation performed by the scrambling circuit 9. Stateddifferently, the descrambling circuit 31 cannot perform descrambling ifthere is no copying management information read out by the copyingmanagement information readout circuit from the data sector header orfrom the TOC data area of the TOC sector and supplied via the copyinginformation management circuit 19. The data descrambled by thedescrambling circuit 31 is sent to the expansion decoding circuit 21.Meanwhile, the pre-set value or the initial value of the descramblingcircuit 321 can also be set on the basis of the key informationspecified by the copying management information.

Similarly to the scrambling circuit 9, a digital descrambling circuit32, fed with digital data from the expansion decoding circuit 21,performs digital descrambling on digital video data from the expansiondecoding circuit 21 based on the copying management information. Thisoutputs descrambled digital video data from the digital descramblingcircuit 32 at the digital interfacing circuit 26. It is also possiblewith the digital descrambling circuit 32 to perform descrambling basedon the key information specified by the copying management information.

In connection with digital dubbing, in which digital data reproducedfrom a signal recorded on an optical disc, that is a digital recordmedium, is recorded as digital data in another digital record medium,there is known a technique of recording a pre-set ID bit, such as thatdiscussed in relation with the prior art, on an optical disc as thecopying management information, with a view to prohibiting unauthorizedcopying. However, unauthorized copying can be easily realized if thecopying management information is skipped in reading.

If, in the embodiment of the present invention, the copying managementinformation is skipped in reading the copying management informationfrom the data sector header or TOC data area, with a view tounauthorized copying, the digital data recorded on the optical disc hasbeen scrambled based on the copying management information and hencecannot be descrambled, thus prohibiting such unauthorized copying. Inaddition, with the embodiment of the present invention, since thedigital scrambling is performed by the digital scrambling circuit 32 onthe basis of the copying management information, the digital scrambleddigital data is copied by digital dubbing. However, the above copyingmanagement information is required for descrambling. This again iseffective to prohibit unauthorized copying.

In the above-described embodiment, the digital scrambling circuit 32 isprovided upstream of the digital interfacing circuit 26. However, aswitch 33 may also be provided in place of the scrambling circuit 32.If, in such case, the contents of the copying management informationindicate copying prohibition, and the switch 33 is controlled to beturned off, digital video data is not outputted by the digitalinterfacing circuit 26, thus enabling the prohibition of unauthorizedcopying in the case of digital copying. If such switch 33 is used, thesignal sent from the copying information management circuit 19 to theswitch 33 is a switch setting control signal corresponding to thecontents of the copying management information.

If, in the digital dubbing, the bit CM_(C) of the copying managementinformation for copying generation limitation permits copying of thecurrent generation, digital data may directly be outputted without thedigital scrambling circuit 32 performing the digital scramblingoperation, that is, with the switch 33 being turned on, if such switch33 is provided. However, in the embodiment of FIG. 2, since the bitCM_(M) in any case is of a value inhibiting digital copying, the switch33 is not turned on in the embodiment of FIG. 2.

FIG. 7 shows an embodiment in which the copying is inhibited by theswitch 22, without performing scrambling or descrambling such as onedescribed above.

In the embodiment of FIG. 7, data compressed in volume and formed intosectors by the compression encoding circuit 2 in the mastering step 30is directly sent to a copying management information appendage circuit,that is an appendage circuit 4 for appending the copying managementinformation in a TOC and an appendage circuit 5 for appending thecopying management information in the data sector header. In thereproducing device 50, digital video data resolved into sectors by thesector resolution circuit 16 is directly sent to the expansion decodingcircuit 21 via a copying management information readout circuit, that isread-out circuits 17 and 18 for reading out the copying managementinformation from the TOC data area and the data sector header,respectively. The digital data from the expansion decoding circuit 21 issent via the switch 22 to the digital interfacing circuit 26. A decisionsignal from the copying information management circuit 19 is sent to theprotect signal generating circuit 20, while being sent as a switchingcontrol signal to the switch 22. The present embodiment is otherwisesimilar in structure to the embodiment of FIG. 1, so that correspondingportions are denoted by the same reference numerals and thecorresponding description is not made for clarity.

If, in the embodiment of FIG. 7, the above result of decision indicatescopying inhibition, the switch 22 is turned off by a switching controlsignal corresponding to the result of decision. Meanwhile, if thegeneration limitation bit CM_(C) of the copying management informationspecifies that the disc is not an original disc and is of a generationspecifying copying inhibition, a switching control signal which turnsoff the switch 22 is outputted by the copying information managementcircuit 19. This inhibits outputting of digital video data from thedigital interfacing circuit 26, so that it becomes possible to prohibitunauthorized copying in digital dubbing in which digital data reproducedfrom a signal recorded on an optical disc D (digital disc medium) isdirectly recorded as digital data on a separate digital disc medium.

With the embodiment of the present invention, in case of digital oranalog copying by the intermediary of an analog interface, in whichdigital video data recorded on an original digital record medium isreproduced and D/A converted into analog video signals, these D/Aconverted analog signals are transmitted via an analog interface havingan analog output or an analog input terminal, and the analog videosignals are subsequently again A/D converted to digital video signalsfor digital recording, or the analog video signals are directlyanalogically recorded, unauthorized copying may be prohibited bygenerating a protect signal as explained later by referring to FIGS. 8,10 and 12 by the protect signal generating circuit 20 and by mixing theprotect signal in the analog video signals by the mixing circuit 24.

Referring first to FIGS. 8 and 9, inhibition of unauthorized copying isexplained in connection with a case in which digital vide data recordedon a digital record medium is reproduced and once D/A converted intoanalog video signals, these analog video signals being again A/Dconverted by the intermediary of an analog interface to digital videosignals, which are recorded as digital data.

In the following description, it is assumed that the generationlimitation bit CM_(C) of the copying management information allows onlyfor one-generation copying, that is, it does not permit reproduction ofcopied data as from the second and following generations, as countedfrom the original.

In the reproducing apparatus 50 for an optical disc D shown in FIG. 9,the copying information management circuit 19 decides whether the bitCM_(M) of the copying management information specifies inhibitioncopying of both analog and digital data or only digital data, and alsowhich generation the bit CM_(C) specifies as copying generationlimitation. A decision signal corresponding to the result of decision issent to the protect signal generation circuit 20.

If the bit CM_(M) of the copying management information does not specifyinhibition of analog copying, and the generation limitation bit CM_(C)specifies that the disc is an original disc, a protect code signalgenerating circuit 74 within the protect signal generation circuit 20generates and outputs a protect code signal PCS specifying that effectby plural coded bits.

This protect code signal PCS is sent to the mixing circuit 24 which thenmixes the protect code signal PCS in a pre-set horizontal period withina vertical blanking period of an analog video signal, as shown in FIG.8. Meanwhile, the protect code signal PCS is inserted at the 20Hthhorizontal period and at the 283Hth horizontal period, where H denoteshorizontal period, for an odd field and for an even field, respectively.The protect code signal PCS, mixed into the analog video signal, is madeup of, for example, 14-bit data and 6-bit error detection correctioncode (CRCC), wherein the 8 bits following the 4-bit header in the 14-bitdata are allocated in the similar manner to the copying managementinformation described previously. The analog video signal, having theanalog protect code signal appended thereto, is outputted at an analogoutput terminal 29.

The analog output terminal 29 of the reproducing apparatus 50 isconnected to an analog input terminal 81 of an optical discrecording/reproducing apparatus 80, employing a recordable optical discRD as a record medium, as an example of a video signal reproducingapparatus. The analog video signal with the appended protect codesignal, outputted by the output terminal 29 of the reproducingapparatus, is A/D converted by the disc recording/reproducing apparatus80 into digital video data which is digitally recorded on the opticaldisc DD. That is, the recording for this case is the first generationcopying from an original disc.

With the optical disc recording/reproducing apparatus 80, the analogvideo signals supplied via the analog input terminal 81 is converted byan A/D conversion circuit 82 into digital video data which is sent to acompression encoding circuit 83, where it is encoded for compressionaccording to the MPEG2 standard and formed into sectors in terms of 2048bytes as a unit. The data encoded for compression in the compressionencoding circuit 83 and formed into sectors is sent to a scramblingcircuit 85.

The analog video signal, to which the protect code has been appended andwhich has been supplied to the analog input terminal 81, is also sent toa protect code signal detection circuit 88. The protect code signaldetection circuit 88 detects the possible presence of the protect codesignal appended to the vertical blanking period of the analog videosignal as shown in FIG. 8 and the state of the protect code signal andnewly generates the copying management information based on the detectedprotect code signal. The protect code signal supplied at this time tothe protect code signal detection circuit 88 specifies that the disc iscopied from the original disc and is permitted for the first generationcopying as counted from the original disc.

Thus the protect code signal detection circuit 88 modifies thegeneration limitation bit CM_(C) of the copying management informationto a value specifying that the disc is a first generation copy ascounted from the original disc, and outputs the modified value.

The copying management information from the protect code signaldetection circuit 88 is sent to the scrambling circuit 85 and to thecopying management information appendage circuit.

Similarly to the scrambling circuit 9 of FIG. 1, the scrambling circuit85 scrambles output data of the compression encoding circuit 83 based onthe copying management information from the protect code signaldetection circuit 88. The scrambled data from the scrambling circuit 85is sent to the copying management information appendage circuit.Meanwhile, a ciphering circuit may be used in place of the scramblingcircuit 85. The copying management information appendage circuit has anappendage circuit 86 for appending the copying management informationinto the TOC and an appendage circuit 87 for appending the copyingmanagement information into the data sector header, as explainedpreviously. The scrambled data, having the copying managementinformation appended thereto as previously explained by the copyingmanagement information appendage circuit, is sent to anencoder/modulation circuit 89.

The encoder/modulation circuit 89 performs data delaying and paritycalculation operations on the supplied data for appending parity dataand converts the resulting data in accordance with a pre-set modulationsystem from, for example, 8-bit data into 16 channel bit modulated data.The encoder/modulation circuit 89 appends synchronization signals of aso-called out-of-rule pattern violating the modulation rule of thepre-set modulation system, in terms of a pre-set data amount as a unit,and sends the resulting data to an optical head device 90.

The optical head device 90 effects optical recording by radiating alaser beam excited based on data supplied from the encoder/modulationcircuit 89 to the recordable optical disc RD run in rotation by arotation servo controlled spindle motor 91. For recording on the opticaldisc RD, so-called magneto-optical recording may be used, in which casea magnetic head is provided facing the optical head device 90 with theoptical disc RD in-between and the laser beam of a power high enough toheat a magnetic film formed on the optical disc RD to a temperaturehigher than the Curie temperature ia radiated on the optical disc RD,while the magnetic head is driven based on the signal from theencoder/modulation circuit 89. In this manner, digital video data,corresponding to the digital video data from the original disc processedthrough the analog interface, is copied on the optical disc RD.

Next, if the optical disc RD, to which digital video data has beencopied from the original disc, is reproduced and D/A converted intoanalog video signals, which are again converted by A/D conversion todigital video data, which in turn is recorded on a separate recordableoptical disc RD, by way of performing the second-generation copying, thefollowing measures are used to render data reproduction from the opticaldisc RD infeasible even if such second generation copying is performed.That is, if the disc RD, on which the first generation copying has beenperformed, is again loaded on the reproducing apparatus 50 of FIG. 9 forreproduction, and the analog video signal resulting from thereproduction is again copied by the optical disc recording/reproducingapparatus 80 shown in FIG. 9, the following measures are used.

That is, data read out from the optical disc RD by the reproducingapparatus 50 from the optical disc RD to which the first generationcopying has been done as described above, is sent to the copyingmanagement information readout circuits 17, 18, in the same way asexplained previously. The copying management information taken out fromthe readout circuits 17, 18 is sent to the copying managementinformation decision circuit 19.

A decision signal from the copying management information decisioncircuit 19 is sent to the protect signal generation circuit 20 fromwhich the protect code signal PCS is generated and outputted to themixing circuit 24. The mixing circuit 24 is fed with an analog videosignal descrambled by the descrambling circuit 31, processed by theexpansion decoding circuit 21 and D/A converted by the D/A conversioncircuit 23. The protect code signal PCS is mixed by the mixing circuit24 with the analog video signal and the resulting signal is outputted atthe analog output terminal 29.

The analog output terminal 29 of the reproducing apparatus 29 isconnected to the analog input terminal 81 of the optical discrecording/reproducing apparatus 80, such that the analog video signalhaving the program code signal appended thereto, outputted at the analogoutput terminal 9 of the reproducing apparatus 50, is supplied to theanalog input terminal 81 of the disc recording/reproducing apparatus 80.

The disc recording/reproducing apparatus 80 converts the analog videosignals supplied via analog input terminal 81 into digital video data bythe A/D conversion circuit 82, and the compression encoding circuit 83then performs compression encoding and formation into sectors on theresulting digital video data. The resulting data is sent to thescrambling circuit 85.

The analog video signal supplied to the analog input terminal 81, havingthe protect code signal appended thereto, is also sent to the protectcode signal detection circuit 88.

The protect code signal, supplied at this time to the protect codesignal detection circuit 88, specifies that the optical disc is thefirst generation copy disc. The protect code signal detection circuit 88converts the generation limitation bit CM_(C) of the copying managementinformation to a value specifying that the disc is the second generationdisc from the original disc, and outputs the resulting modified value.

The copying management information from the protect code signaldetection circuit 88 is sent to the scrambling circuit 85 and to thecopying management information appendage circuit. The scrambling circuit85 scrambles output data of the compression encoding circuit 83 based onthe copying management information from the protect code signaldetection circuit 88, in a manner as explained previously. The copyingmanagement information appendage circuit appends the copying managementinformation to scrambled data from the scrambling circuit 85 and outputsthe resulting data.

If a ciphering circuit is used in place of the scrambling circuit 85,the protect code signal detection circuit 88 outputs a control signalfor enabling ciphering by the ciphering circuit. The control signal maybe the key information for ciphering. This outputs the ciphered digitalvideo signal from the ciphering circuit.

Output data of the copying management information appendage circuit iscorrected for errors and modulated by the encoder/modulation circuit 89and thence supplied to an optical heads device 90 or a magnetic head foroptical or magneto-optical recording in a manner as explainedpreviously.

The optical disc RD, on which the second generation copying has beendone as described above, is read out by the optical head device 90 ofthe optical disc recording/reproducing apparatus 80. The read-out datais sent to the reproducing system of the optical discrecording/reproducing apparatus 80.

A digital reproducing circuit 92 of the reproducing system has, inaddition to main components, such as an RF circuit 12, demodulationcircuit 14, an error correction circuit 15, a sector resolution circuit16 and an expansion/decoding circuit 21, the above-mentioned copyingmanagement information readout circuit, copying management informationdecision circuit 19 and the descrambling circuit 31.

The copying management information decision circuit of the digitalreproducing circuit 92 discriminates the generation limitation bitCM_(C) of the copying management information read out from the opticaldisc RD and thus learns that the optical disc RD is a second generationcopy disc. At this time, the copying management information decisioncircuit 19 of the digital reproducing circuit 92 is designed not tooutput the copying management information to the descrambling circuit31, or to output the non-scramblable copying management information.

Thus the data sent to the expansion decoding circuit 21 in the digitalreproducing circuit 92 is the non-descrambled data, so that, if the datais expanded and decoded by the expansion decoding circuit 21, regulardigital video data cannot be produced.

With the above-described arrangement, in such a case wherein digitalvideo data recorded on the original digital record medium is reproducedand temporarily D/A converted into analog video signals, which are againA/D converted into digital video data for digital recording, generationlimitation becomes possible to prevent unauthorized copying. In theabove case, the second generation data copying can be done on theoptical disc RD. However, since the recorded data is not descrambleddata, regular pictures cannot be obtained if the data is reproduced anddisplayed on a television receiver 71, thus prohibiting unauthorizedcopying.

If, in the case of digital copying via the analog interface, the copyingmanagement information is skipped in reading during reproduction of theoptical disc RD by the reproducing apparatus 50 with a view tounauthorized copying as described above, since the digital data recordedon the optical disc RD is scrambled on the basis of the copyingmanagement information, the descrambling circuit 31 cannot descramblethe data, while a protect code generation circuit 74 cannot generate theprotect code signal based on the copying management information, thusenabling prohibition of unauthorized copying. That is, since the opticaldisc recording/reproducing apparatus 80 cannot generate the copyingmanagement information based on the protect code signal, the scramblingcircuit 85 cannot descramble data, thus enabling prevention ofunauthorized copying. It may be envisaged to mask the protect codesignal instead of skipping the reading of the copying managementinformation with a view to unauthorized copying. In this case, thescrambling circuit 85 of the optical disc recording/reproducingapparatus 80 cannot descramble the data, thus assuring prevention ofunauthorized copying.

In the above example, the first generation copying from the originaldisc is permitted. However, if the generation limitation bit CM_(C) ofthe copying management information is selected for inhibiting the firstgeneration copying, the first generation copying from the original discis prohibited.

Also, in the above example, an optical disc RD recordable on therecording/reproducing apparatus 80 is used. Of course, similarprevention of copying can be achieved with a digital video datarecording/reproducing apparatus for a video tape TP.

With the above example, the digital video data recorded on the originaldigital record medium is reproduced and temporarily converted intoanalog video signals which are again A/D converted into digital videosignals for digital recording. However, unauthorized copying can beprohibited if an analog video signal is recorded as it is analogically.

Referring to FIGS. 10 and 11, prevention of unauthorized copying isexplained for a case in which digital video data recorded on an originaldigital record medium is reproduced and transiently D/A converted intoanalog video signals which are then analogically recorded on aconventional analog video tape recorder (analog VTR).

It is assumed in such case that, with the reproducing apparatus 50 forthe optical disc D shown in FIG. 11, the bit CM_(M) of the copyingmanagement information indicates inhibition of copying, and the decisionsignal from the decision circuit 19 indicates inhibition of analogicalcopying. It is also assumed that an analog protect pulse APP, which is awhite peak signal, is generated by a protect pulse generating circuit 72in the protect signal generating circuit 20. This analog protect pulseAPP is mixed by the mixing circuit 24 in a pre-set period of thevertical blanking period of the analog video signal, as shown in FIG.11. The protect pulse generating circuit 72 also generates the analogprotect pulse APP if the copying management information is not supplied.A decision signal corresponding to the inhibition of analog copying isoutputted by the copying management information decision circuit 19 evenif the generation limitation bit CM_(C) denoted by the copyingmanagement information specifies inhibition of analog copying of thecurrent generation. The system of inhibiting analog copying is termedthe analog protection system (APC).

An output signal of the mixing circuit 24 is such a signal in whichplural pairs of positive pulses and pseudo synchronization pulses of apre-set sequence are appended to the video signal in the verticalblanking period of the analog video signal next to the synchronizationpulse. In the illustrative case of FIG. 10, plural pulse pairs of apseudo synchronization pulse P₁₂ and a positive pulse, such as a whitepeak pulse, are inserted next to two equalizing pulses P₁₀ in ahorizontal line (horizontal period). The technique of using acombination signal of these plural pseudo synchronization pulses andplural white peak signals as a recording scrambling signal is disclosedin JP Patent Kokai Publication JP{circumflex over ( )}A-61-288582(1986). The analog protection system (APS) employing this pseudo-syncpulse (PSP) is termed the PSP system.

The reason the normal picture recording becomes impossible on a usualvideo tape recorder (VTR) is now briefly explained.

It is assumed that the analog output terminal 29 of the reproducingapparatus 50 is connected to the analog input terminal 61 of the analogVTR 60, and the analog video signals, having appended thereto the aboverecording scrambling signal outputted by the analog output terminal 29of the reproducing apparatus 50, are recorded on the video tape TP by ananalog VTR 60.

Usually, the analog VTR 60 has an automatic gain control (AGC) circuit62, as automatic amplitude adjustment means or automatic gain adjustmentmeans, and is configured for automatically adjusting the amplitude ofthe analog video signal entering the analog input terminal 61. If theanalog video signal shown in FIG. 10 is supplied to the analog VTR 60provided with such AGC circuit 62, the AGC circuit 62 responds to thewhite peak signal added in the vertical blanking period, thus narrowingthe inherent video signal amplitude. That is, the AGC circuit 62 of ausual video tape recorder cannot distinguish the equalizing pulse P₁₀from the pseudo synchronization pulse P₁₂ and hence samples the level ofthe appended positive pulse P₁₄ such that it recognizes the positivepulse level as being several times as large in amplitude as the inputsignal level and manages control to lower the gain. If the analog videosignal, automatically adjusted in amplitude by the AGC circuit 62, isrecorded via the analog recording circuit 65 on the video tape TP, andsubsequently reproduced by an analog reproducing circuit 67 in thetelevision receiver 70 via an analog output terminal 68, an extremelyill-looking picture is produced due to unusual lightness level in thereproduced picture.

In this manner, inhibition of unauthorized copying, inclusive ofgeneration limitation, becomes possible for a case in which digitalvideo data recorded on an original digital record medium is reproducedand transiently D/A converted into analog video signals which are thenanalogically recorded on a conventional analog VTR.

If, in such analog copying via analog interface, the copying managementinformation is skipped in reading during reproduction of the opticaldisc RD in the reproducing apparatus 50 with a view to unauthorizedcopying in a manner as described above, the digital data recorded on theoptical disc RD is scrambled based on the copying managementinformation, and hence cannot be descrambled by the descrambling circuit31. In addition, the protect code generating circuit 74 is designed togenerate the protect pulse even if the copying management information isnot supplied, thus enabling unauthorized copying.

In the example of the analog VTR 60 of FIG. 11, the reaction of the AGCcircuit 62 to the analog protect pulse APP is utilized. However, if adetection circuit 63 for detecting the analog protect pulse APP from theanalog video signal supplied via analog input terminal 61 to the analogVTR 60 is provided, a switch 64 is provided, such as downstream of theAGC circuit 62, and the switch 64 is turned off on detection of theanalog protect pulse APP, it becomes possible to inhibit unauthorizedcopying. That is, if the switch 64 is turned off, the analog videosignal supplied to the analog input terminal 61 cannot be recorded onthe video tape TP, it becomes possible to inhibit unauthorized copying.

In the above embodiment, description has been made on an analog VTRemploying a video tape TP. It should however be noted that theabove-described technique for copying inhibition can be utilized for ananalog video disc recording/reproducing apparatus employing an analogvideo disc AD.

In addition, according to the present invention, unauthorized copyingcan be inhibited both for a case in which the analog video signals areagain A/D converted, transmitted via an analog interface andsubsequently restored to digital video data which is digitally recorded,and for a case in which the analog video signals are transmitted viaanalog interface and directly recorded analogically, as shown in FIGS.12 and 13.

Specifically, the copying management information decision circuit 19 inthe reproducing apparatus 50 for the optical disc D includes a decisioncircuit 71 for discriminating the state of the bit CM_(M) of the copyingmanagement information, and a decision circuit 73 for discriminating thebit CM_(C) of the copying management information. The decision signalsfrom the decision circuits 71, 73 are sent to the protect signalgenerating circuit 20, while the copying management information is sentto the descrambling circuit 31 and to the digital scrambling circuit 32.

The descrambling circuit 31 and the digital scrambling circuit 32perform the operations similar to those explained previously.

The protect signal generating circuit 20 includes a protect pulsegenerating circuit 72 for generating the analog protect pulse APP basedon the decision signal from the decision circuit 71, and a protect codesignal generating circuit 74 for generating the protect code signal PCSbased on the decision signal from the decision circuit 71. The analogprotect pulse APP from the protect pulse generating circuit 72 and theprotect code signal PCS from the protect code signal generating circuit74 are sent to the mixing circuit 24.

Thus the mixing circuit 24 outputs a signal corresponding to an analogvideo signal in a pre-set period in the vertical blanking period ofwhich the above protect code signal PCS is mixed and on plural pseudosynchronization pulses (pseudo equivalent pulses) of which plural whitepeak signal are combined, as shown in FIG. 12.

The above signal, that is the analog video signal having the protectcode signals PCS and the analog protect pulses APC appended thereto, isoutputted at the analog output terminal 29.

The analog output terminal 29 of the reproducing device 50 is connectedto the analog input terminal 81 of the optical discrecording/reproducing apparatus 80 and to the analog input terminal 61of the analog VTR 60. The analog VTR 60 analogically records the analogvideo signals on the video tape TP, while the optical discrecording/reproducing apparatus 80 converts the analog video signalsinto digital video signals which are recorded on the optical disc RD.The recording/reproducing operation by the analog VTR 60 and the opticaldisc recording/reproducing apparatus 80 is similar to that describedabove and hence is not explained in detail. It is noted that the opticaldisc recording/reproducing apparatus 80 detects not only the protectcode signal PCS but also the analog protect pulse APP in the protectcode detection circuit 88 and, on detection of the analog protect pulseAPP, performs scrambling by the scrambling circuit 85, for prohibitingunauthorized copying.

A modified embodiment of the present invention will now be explained.

Various modifications my be made in the illustrative examples of thecopying management information shown in FIG. 2, scrambling circuit shownin FIG. 3 and the sector format shown in FIGS. 5 and 6.

FIG. 14 shows a modification of the copying management information. Ofthe eight bits b7 to b0, upper two bits of b7 and b6 are allocated asthe information bits CM_(C) of the copying generation management system(CGMS) for limiting the copying generation, the next two bits b5 and b4are allocated as trigger bits CM_(T) of the analog protection system(APS) and the next bit b3 is allocated as the bit CM_(A) specifyingwhether or not the source is an analog source. The remaining two bits b2to b0 are undefined. If the bits (b7, b6) of the APS trigger bits CM_(T)are (0, 0), (1, 0), (1, 1) or (0, 1), these specify copy free, onegeneration copying possible, copy not permitted and unused,respectively. If the bits (b5, b4) of the APS trigger bits CM_(T) are(0, 0), (0, 1), (1, 0) or (1, 1), these specify off state, turning thepseudo-sync pulse and a split burst or color stripe as later explainedon and off, respectively, turning the PSP and the 2-line split burst on,and turning the PSP and the 4-line split burst on, respectively. If thebit b3 of CM_(A) is 1 or 0, it specifies an analog package medium andotherwise, respectively.

The contents of the APS trigger bit turning the PSP on means that theanalog protect pulse APP shown in FIGS. 10 and 12 be inserted in apre-set period of the vertical blanking period, such as a period between12 H and 19 H. The split burst being on means that the color burstinserted on the trailing side of the horizontal blanking pulse in thehorizontal blanking period be partially reversed, while the two-linesplit burst on means reversing color burst two lines on end every 17lines. The four-line split burst on means reversing color burst fourlines on end every 21 lines. The color burst reversion is an operationof reversing a portion, for example, a forward half portion, of thecolor burst signal, or changing its phase. Such reversed split colorburst produces color interference, such as generation of color stripes,in the copied color video signals.

FIG. 15 illustrates the reversed split color burst APS. In a line inwhich the color burst is reversed, part of the color burst CB, as areference signal of the color sub-carrier arrayed on the trailing sideof the horizontal synchronization pulse HD, such as a hatched portion inFIG. 15, is reversed in phase. That is, the color burst period C_(N) inthe standard NTSC system is 9 cycles. To the front side of the standardperiod C_(N) of the color burst is connected a burst signal of, forexample, two cycles, as a pre-period C_(P), to provide a sum total of 11cycles. The two cycles of the pre-period C_(P) and 3.5 cycles of thefront period C_(F) of the former half portion in the color burststandard period C_(N), totalling at 5.5 cycles, are reversed in burstphase, while 5.5 cycles of the latter back portion C_(B) in the colorburst standard period C_(N) remain intact.

The color burst signal, partially reversed in phase, is generated in,for example, the protect pulse generating circuit 72 of FIGS. 11 or 12and sent to the mixing circuit 24, where the phase reversed color burstsignal is mixed two lines on end every 17 lines for two line split burston, while being mixed four lines on end every 21 lines for four linesplit burst on.

As for the split burst operation, part of the color burst is reversed inphase, that is by 180°. However, the color burst phase may also bechanged by 90° or 270° or by an optional angle. The period of phasechange can be set optionally without being limited to 5.5 cycles.

FIG. 16 shows another illustrative example of a scrambling circuit whichmay be used in place of the above-described scrambling circuit shown inFIG. 3. In the illustrative example of FIG. 16, the 15-bit shiftregister 41 for scrambling is similar to the illustrative example shownin FIG. 3 except that feedback conforming to the generating polynominalx¹⁵+x⁴+1 is employed, using an exclusive-OR (ExOR) gate 42. Thus thecommon portions are denoted by the same reference numerals and thecorresponding description is omitted for simplicity.

In place of the illustrative example of the sector format shown in FIGS.5 and 6, a sector format shown in FIG. 17 may be used.

In the embodiment of FIG. 17, each sector is made up of 12 rows, eachrow being made up of 172 bytes, thus totalling at 2064 bytes, of which2048 bytes represent main data. At the leading position of the first of12 rows, 4-byte ID (identification data), 2-byte IED (ID error detectioncode) and a 6-byte RSV (spare) are arrayed in this order. A 4-byte errordetection code (EDC) is arrayed at the terminal position of the lastrow.

Of the 4 bytes of ID (identification data), the first MSB side byte(bits b31 to b24) represent the sector information, with the remainingthree bytes (bits b23 to b0) represent the sector numbers, as shown inFIG. 18. The sector information is made up of a 1-bit sector formattype, a 1 bit of the tracking method, a 1 bit of reflectance, a 1 bitspare, 2 bits of area types and 2 bits of the layer number, looking fromthe MSB side.

The copying management information may be provided at a pre-set positionin the sector format. For example, in a sector format of the data area,a byte of the 6 bytes of RSV may be used, whereas, in a sector format inthe TOC area, several bytes or several tens of bytes of the main dataportion may be collected and used as an area for the copying managementinformation.

The above description has been made in connection withrecording/reproduction on or from an optical disc or a video tape. Forexample, if digital data, in which part of the transmission controlinformation similar to the copying management information is transmittedas the key information, is scrambled or ciphered, and the transmissioncontrol information is transmitted by being annexed to the ciphereddigital data, unauthorized copying can be prevented from occurring. Thesignal transmission apparatus corresponding to the signal transmissionmethod of the present invention may be similar to the arrangements shownin FIGS. 1, 9, 11 and 13 if the encoder/modulation circuit is changed toa unit performing encoding or modulation conforming to the transmissionsystem and the optical head device or the interfacing means forrecording/reproduction is changed to data transmission or data receptionmeans.

In addition, although the ciphering is done solely byscrambling/descrambling in the above-described embodiment, it can alsobe done by other conversion operations.

On the other hand, although the conversion on the recording side of FIG.1 is performed by the scrambling circuit 9, it may also be performed inthe compression encoding circuit 2 or in the encoder/modulation circuit6. In such case, the conversion operation on the reproducing side issimilarly performed by one of the demodulation circuit 14, errorcorrection circuit 15, sector resolution circuit 16 and the expansiondecoding circuit 21, in place of by the descrambling circuit 31. If theconversion operation is performed by one of the demodulation circuit 14,error correction circuit 15, sector resolution circuit 16 and theexpansion decoding circuit 21, it is necessary to acquire theinformation necessary in making decision in the copying managementinformation decision circuit 19 in advance. Since the TOC information isacquired first, the information derived from the TOC information may beemployed.

With the above-described arrangement of the present invention, itbecomes possible to combat unauthorized copying for the analog copyingand digital copying simultaneously.

Although the optical disci and the video tape are used as the signalrecord medium in the above description, it is also possible to usemagnetic recording media, such as so-called IC cards, hard discs orflexible discs, while it is possible to use an optical disc of the typein which recording is done by pits. In addition, a phase change typeoptical disc, an organic dye type optical disc, an optical disc recordedby UV laser light or optical discs having multi-layer recording films,may be used, in addition to the magneto-optical discs. A variety oftape-shaped recording media, such as video tapes, may also be employed.

What is claimed is:
 1. A method for reproducing digital data from asignal record medium, comprising the steps of: reading out recordingcontrol information from a playback mode control signal area of saidsignal record medium, said recording control information indicating theplayback mode of said record medium; and performing a pre-set conversionoperation on an analog signal, generated from said digital data, basedon said recording control information.
 2. The method according to claim1, wherein said digital data is partitioned into sectors and saidplayback mode control signal area includes at least one of said sectors.3. The signal reproducing method as claimed in claim 1 wherein saidpre-set conversion operation is performed on said digital data based onsaid recording control information.
 4. The signal reproducing method asclaimed in claim 3 wherein the pre-set conversion operation on saiddigital data is a digital descrambling operation.
 5. The signalreproducing method as claimed in claim 3 wherein said digital data isciphered data and said pre-set conversion operation on said digital datais an operation of deciphering the digital data using at least a portionof the recording control information.
 6. The signal reproducing methodas claimed in claim 3 wherein said digital data is ciphered data andsaid pre-set conversion operation on said digital data is an operationof deciphering said digital data according to decoding means specifiedby at least a portion of said recording control information.
 7. Thesignal reproducing method as claimed in claim 1 wherein said analogsignal is an analog video signal and wherein the pre-set conversionoperation includes arraying a combination signal of plural pseudosynchronization pulses and plural white peak signals across pluralhorizontal periods in a vertical blanking period of said analog videosignal.
 8. The signal reproducing method as claimed in claim 1 whereinsaid analog signal is an analog color video signal and wherein saidpre-set conversion operation includes changing the phase of at least aportion of a color burst signal associated with said color video signal.9. The signal reproducing method as claimed in claim 1 wherein thepre-set conversion operation includes arraying a signal coded withplural bits at a pre-set position in the analog signal.
 10. The signalreproducing method as claimed in claim 9 wherein said analog signal isan analog video signal and said pre-set position is a predeterminedhorizontal period within a vertical blanking period of said analog videosignal.
 11. The signal reproducing method as claimed in claim 9 whereinsaid coded signal includes a recording limitation signal indicating alimitation on recording.
 12. An apparatus for reproducing digital datafrom a signal recording medium, comprising: means for reading outrecording control information from a playback mode control signal areaof said signal recording medium, said recording control informationindicating the playback mode of said record medium; and means forperforming a pre-set conversion operation on an analog signal, generatedfrom said digital data, based on said recording control information. 13.The apparatus according to claim 12, wherein said digital data ispartitioned into sectors and said playback mode control signal areaincludes at least one of said sectors.
 14. The signal reproducingapparatus as claimed in claim 12 wherein said pre-set conversionoperation is performed on said digital data based on said recordingcontrol information.
 15. The signal reproducing apparatus as claimed inclaim 14 wherein the pre-set conversion operation on said digital datais a digital descrambling operation.
 16. The signal reproducingapparatus as claimed in claim 14 wherein said digital data is ciphereddata and said pre-set conversion operation on said digital data is anoperation of digitally converting said digital data.
 17. The signalreproducing apparatus as claimed in claim 14 wherein said digital datais ciphered data and said pre-set conversion operation on said digitaldata is an operation of deciphering said digital data according todecoding means specified by at least a portion of said recording controlinformation.
 18. The signal reproducing apparatus as claimed in claim 12wherein said analog signal is an analog video signal and wherein thepre-set conversion operation includes arraying a combination signal ofplural pseudo synchronization pulses and plural white peak signalsacross plural horizontal periods in a vertical blanking period of saidanalog video signal.
 19. The signal reproducing apparatus as claimed inclaim 12 wherein said analog signal is an analog color video signal andwherein said pre-set conversion operation includes changing the phase ofat least a portion of a color burst signal associated with said colorvideo signal.
 20. The signal reproducing apparatus as claimed in claim12 wherein the pre-set conversion operation involves arraying a signalcoded with plural bits at a pre-set position in the analog signal. 21.The signal reproducing apparatus as claimed in claim 20 wherein saidanalog signal is an analog video signal and said pre-set position is apredetermined horizontal period within a vertical blanking period ofsaid analog video signal.
 22. The signal reproducing apparatus asclaimed in claim 20 wherein said coded signal includes a recordinglimitation signal indicating a limitation on recording.
 23. A method forrecording a signal, comprising the steps of: generating recordingcontrol information for supervising recording of said signal on a signalrecord medium; ciphering said signal using at least a part of saidrecording control information as key information; arraying saidrecording control information at a pre-set position of a playback modecontrol signal area of said signal record medium, said recording controlinformation indicating the playback mode of said record medium; andrecording on said signal record medium said recording controlinformation arrayed at the pre-set position of said playback modecontrol signal area along with said ciphered signal.
 24. The methodaccording to claim 23, wherein said digital data is partitioned intounits and said playback mode control signal area includes at least oneof said units.
 25. A signal recording apparatus comprising: recordingcontrol information generating means for generating recording controlinformation for supervising the recording of said signal on a signalrecord medium; ciphering means for ciphering the signal using at least aportion of said recording control signal as key information; annexingmeans for annexing said recording control information at a playback modecontrol signal area of said signal record medium, said recording controlinformation indicating the playback mode of said record medium; andrecording means for recording said signal on said record medium; whereinsaid recording control information is arrayed at the playback modecontrol signal area on said signal record medium along with the cipheredsignal.
 26. The apparatus according to claim 25, wherein said digitaldata is partitioned into units and said playback mode control signalarea includes at least one of said units.
 27. A signal reproducingapparatus for reproducing a ciphered signal from a signal record mediumcomprising: readout means for reading out recording control informationarrayed at a playback mode control signal area of said signal recordmedium, said recording control information indicating the playback modeof said record medium; and deciphering means for deciphering saidciphered signal using at least a portion of said recording controlinformation as key information.
 28. The apparatus according to claim 27,wherein said digital data is partitioned into units and said playbackmode control signal area includes at least one of said units.
 29. Thesignal reproducing apparatus as claimed in claim 27 further comprisingconversion means for performing a pre-set conversion on the decipheredsignal using at least a portion of said recording control information askey information.
 30. The signal reproducing apparatus as claimed inclaim 29 wherein the deciphered signal is an analog video signal andwherein said pre-set conversion includes arraying a combination signalof plural pseudo synchronization pulses and plural white peak signalsover plural horizontal periods within a vertical blanking period of theanalog video signal.
 31. The signal reproducing apparatus as claimed inclaim 29 wherein said deciphered signal is an analog color video signaland wherein said pre-set conversion operation includes changing thephase of at least a portion of a color burst signal associated with saiddeciphered signal.
 32. The signal reproducing apparatus as claimed inclaim 29 wherein the deciphered signal is an analog signal and whereinsaid pre-set conversion operation includes arraying a signal coded withplural bits at a pre-set position in the analog signal.
 33. The signalreproducing apparatus as claimed in claim 32 wherein said analog signalis an analog video signal and said pre-set position is a predeterminedhorizontal period within a vertical blanking period of said analog videosignal.
 34. The signal reproducing apparatus as claimed in claim 32wherein said coded signal includes a recording limitation signalindicating a limitation on recording.
 35. A method for receiving andreproducing transmitted digital data, comprising the steps of:generating transmission control information from the received digitaldata; and performing a pre-set conversion on said digital data and on ananalog signal generated from said digital data based on saidtransmission control information.
 36. The method as claimed in claim 35wherein the pre-set conversion of said digital data includes digitallyscrambling said digital data.
 37. The method as claimed in claim 35wherein said digital data is ciphered and wherein said pre-setconversion includes deciphering said digital data using at least aportion of said transmission control information as key information. 38.The method as claimed in claim 35 wherein the digital data is ciphereddata and wherein the pre-set conversion operation includes decipheringsaid digital data via decoding means operated according to at least aportion of said transmission control information.
 39. The method asclaimed in claim 35 wherein said analog signal is an analog video signaland wherein the pre-set conversion operation includes arraying acombination signal of plural pseudo synchronization pulses and pluralwhite peak signals across plural horizontal periods in a verticalblanking period of said analog video signal.
 40. The method as claimedin claim 35 wherein said analog signal is an analog color video signaland wherein said pre-set conversion operation on said analog color videosignal includes changing the phase of at least a portion of a colorburst signal associated with said color video signal.
 41. The method asclaimed in claim 35 wherein the pre-set conversion operation on saidanalog signal includes arraying a signal coded with plural bits at apre-set position in the analog signal.
 42. The method as claimed inclaim 41 wherein said analog signal is an analog color video signal andsaid pre-set position is a predetermined horizontal period within avertical blanking period of said analog video signal.
 43. The method asclaimed in claim 42 wherein said coded signal includes a recordinglimitation signal indicating a limitation on recording.
 44. An apparatusfor receiving and reproducing transmitted digital data, comprising:means for generating transmission control information from the receiveddigital data; and means for performing a pre-set conversion on saiddigital data and on an analog signal generated from said digital databased on said transmission control information, wherein said pre-setconversion operation on said analog signal includes arraying a codedsignal coded with plural bits at a pre-set position in the analogsignal, and said coded signal includes a transmission limitation signalindicating a limitation on transmission.
 45. A record medium comprising:a signal record area for storing a signal; and a playback mode controlsignal area for storing control information, said control informationindicating the recording/reproduction mode whereby said signal isrecorded/reproduced, wherein at least a portion of said controlinformation is ciphered using at least a portion of said controlinformation as key information.
 46. The record medium of claim 45,wherein said playback mode control signal area is partitioned into aplurality of recording units.
 47. The record medium of claim 45, whereinsaid signal is a digital video signal partitioned into sectors and saidplayback mode control signal area includes at least one header of saidsectors.
 48. The record medium of claim 45, wherein the record medium isa digital disc and said playback mode control signal area includes abeginning portion of at least one recording track of said disc.